Decades ago "Brown's Alcohol Cookbook" explained how Brown did something similar with a motorcycle engine by shaving the heads to increase the compression ratio and pressure. This can be done safely because the detonation pressure of ethanol is maybe double that of gasoline. Higher compression pressure means higher burn pressure means higher power output. This means that ethanol, which has less calories than ethane gasoline (because it is essentially partially burned ethane), can put out more power because of the compression pressure/burn pressure increase.

I'm not selling "Brown's Alcohol Cookbook" but I'm pretty sure that he still is. Search for him online.